Spatial variation in insect community and species responses to habitat loss and plant community composition
Spatial variation in insect community and species responses to habitat loss and plant community composition
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DOI：
10.1007/s00442-005-0275-1
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发表时间：
2006-03-01
期刊：
影响因子：
2.7
通讯作者：
Summerville, KS
中科院分区：
文献类型：
--
作者：
Crist, TO;Pradhan-Devare, SV;Summerville, KS
一些实验研究已经研究了物种对生境面积和空间安排的反应，但植物组成和物种分布的空间变化也会影响动物对生境改变的反应。我们采用实验的方法来研究栖息地面积，边缘和植物群落组成的昆虫物种丰富度和组成的空间结构的综合影响。分析了三个功能团（食草动物、捕食者和寄生蜂）和单个物种的丰度。栖息地补丁创建不同的面积和边缘选择性割部分15 mx15米地块在1.7公顷的老领域。空间和环境变量被用来预测昆虫的反应，在单独的多元回归和排序模型。由于空间和环境变量的物种反应的变化，然后通过将这些变量组合成一个整体的回归或排序分区。空间和环境变量的贡献相似的百分比，昆虫物种丰富度，丰度或组成的总方差。在任何响应变量中均未观察到栖息地面积的显著影响。草食动物丰度表现出积极的反应，豆科植物或草覆盖，以及空间变异是无关的环境变量。捕食性天敌和寄生性天敌对植物物种丰富度和生境边缘的影响较大，而不可解释的空间变异较小。个别物种不同的植物变量的反应，这取决于主机专业化或种内聚集。我们的研究强调了植物群落组成和空间变异的重要性，除了环境变量。空间变异既源于物种对环境特征的反应，也源于物种在生境专化和种内聚集方面的差异。
Several experimental studies have examined species responses to manipulations of habitat area and spatial arrangement, but plant composition and spatial variation in species distributions also affect animal responses to habitat alteration. We used an experimental approach to study the combined effects of habitat area, edge, and plant community composition on the spatial structure of insect species richness and composition. The abundance of three guilds (herbivores, predators and parasitoids) and individual species were also analyzed. Habitat patches were created that differed in area and edge by selectively mowing portions of 15 mx15 m plots in a 1.7-ha old field. Spatial and environmental variables were used to predict insect responses in separate multiple regression and ordination models. The variation in species responses due to spatial and environmental variables was then partitioned by combining these variables into an overall regression or ordination. Spatial and environmental variables contributed similar percentages to the total variance in insect species richness, abundance or composition. No significant effects of habitat area were observed in any response variable. Herbivore abundance showed positive responses to legume or grass cover, as well as spatial variation that was unrelated to environmental variables. Predators and parasitoids had greater effects of plant species richness and habitat edge, and less unexplained spatial variation. Individual species differed in their responses to plant variables, depending on host specialization or intraspecific aggregation. Our study highlights the importance of plant community composition and spatial variation apart from environmental variables. Spatial variation stems both from species responses to environmental features as well as species differences in habitat specialization and intraspecific aggregation.